Coolant Fan Control Module 1, Checking
Special tools and workshop equipment required
- Multimeter VAG 1526 or Multimeter VAG 1715
- Connector test kit VAG 1594
- Wiring diagram
Test requirements
- Fuses in E-box (plenum chamber, left) must be OK: Refer to appropriate SYSTEMS WIRING DIAGRAM
- Motronic Engine Control Module (ECM) Power Supply Relay -J271- must be OK, check: appropriate SYSTEMS WIRING DIAGRAM
- Battery voltage must be at least 11.5 volts.
- All electrical consumers such as, lights and rear window defroster must be switched off.
- Parking brake must be engaged or else daylight driving lights will be switched on.
- For vehicles with automatic transmission, selector lever must be in P.
- If vehicle is equipped with an A/C system, it must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
Test sequence
-- Disconnect 4-pin connector from Coolant Fan Control (FC) Control Module -J293- -1-.
Checking voltage supply
-- Connect multimeter to terminals 1+4 and 2+4 of connector for voltage measurement.
-- Switch ignition on.
Specified value: at least 10.0 V
-- Switch ignition off.
If there is no voltage:
-- Check wires between 4-pin connector (terminals 1 and 2) and Motronic Engine Control Module (ECM) Power Supply Relay -J271- for open circuit according to wiring diagram.
Wire resistance: max. 1.5 Ω
-- Check for open circuit in wire between 4-pin connector terminal 4 and Ground (GND) according to wiring diagram.
Wire resistance: max. 1.5 Ω
-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
-- Generate readiness code.
If there is no malfunction in voltage supply:
-- Check wire to Engine Control Module (ECM) according to wiring diagram.
Checking wire to Engine Control Module (ECM)
-- Connect test box to control module wiring harness, connect test box for wiring test.
-- Check wire between test box and 4-pin connector for open circuit according to wiring diagram.
Terminal 3 + socket 66
Wire resistance: max. 1.5 Ω
-- Check wire for short circuit to vehicle Ground (GND) and to B+.
Specified value: ∞ Ω
-- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
-- Generate readiness code.
If no malfunction is detected in wire and there was voltage present between terminals 1+4 and 2+4:
-- Replace Coolant Fan Control (FC) Control Module -J293- with Coolant Fan -V7-.
Final Procedures
After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .